The Haus Resurfacing Machine is by far the best resurfacing machine available. Primarily because of our Rigid Diamond Cutting Wheels. The process of using Rigid Cutting Wheels can actually make a ball rounder than factory specifications. Using soft cutting pads will make flat spots bigger because the pad follows the existing contours of the ball's surface. As far as a soft pad is concerned, a hole in a ball's surface is a flat spot. Rigid cutting wheels do not follow the existing contour of a ball, so they keep or make bowling balls rounder.